<template>
  <view class="viewport">
    <!-- 推荐封面 -->
    <view class="cover">
      <image :src="bannerPicture"></image>
    </view>

    <!-- tab栏 -->
    <view class="tabs">
      <text class="text" v-for="(item, index) in recommendList" :key="item.id" :class="{ active: index === activeIndex }" @tap="changeTabs(index)">
        {{ item.title }}
      </text>
    </view>

    <!-- 列表内容 -->
    <scroll-view scroll-y class="scroll-view" @scrolltolower="handleScrolltolower" v-for="(item, index) in recommendList" :key="index" v-show="activeIndex === index">
      <view class="goods">
        <navigator hover-class="none" class="navigator" v-for="goods in item.goodItems.items" :key="goods.id" :url="`/pages/goods/index?id=${goods.id}`">
          <image class="thumb" :src="goods.picture"></image>
          <view class="name ellipsis">{{ goods.name }}</view>
          <view class="price">
            <text class="symbol">¥</text>
            <text class="number">{{ goods.price }}</text>
          </view>
        </navigator>
      </view>
      <view class="loading">正在加载...</view>
    </scroll-view>
  </view>
</template>

<script>
import { getHomeRecommend } from '@/api/home'
export default {
  data() {
    return {
      // 背景大图
      bannerPicture: '',
      // 当前显示的tab栏
      activeIndex: 0,
      // 列表数据
      recommendList: [
        {
          id: '772990341',
          title: '抢先尝鲜',
          goodItems: {
            counts: 343,
            pageSize: 10,
            pages: 35,
            page: 1,
            items: []
          }
        }
      ]
    }
  },
  async onLoad(ev) {
    const urlMap = {
      1: { title: '特惠推荐', url: '/home/preference/mutli' },
      2: { title: '爆款推荐', url: '/home/inVogue/mutli' },
      3: { title: '一站买全', url: '/home/oneStop/mutli' },
      4: { title: '新鲜好物', url: '/home/new/mutli' } // 后端未提供，暂用新鲜好物url
      // 5: { title: '新鲜好物', url: '/home/new/mutli' }
    }
    let currentItem = urlMap[ev.type]
    uni.setNavigationBarTitle({ title: currentItem.title })

    /** 页面请求 url */
    this.url = currentItem.url
    this.getHomeRecommend()
    /** 正在加载下一页数据 */
    this.isLoading = false
  },
  methods: {
    /** 获取推荐页面数据 */
    async getHomeRecommend() {
      let res = await getHomeRecommend(this.url)
      // console.log(res)
      this.bannerPicture = res.result.bannerPicture
      this.recommendList = res.result.subTypes.map(v => {
        return {
          id: v.id,
          title: v.title,
          goodItems: res.result.goodsItems[v.id]
        }
      })
    },
    /** tab 栏切换 */
    changeTabs(index) {
      this.activeIndex = index
    },

    /** 触底分页 */
    async handleScrolltolower() {
      if (this.isLoading) {
        return
      }
      let tabItem = this.recommendList[this.activeIndex]
      let { page, pageSize } = tabItem.goodItems
      let subType = tabItem.id
      page++
      /** 当不是最后一页时，请求数据 */
      if (page < tabItem.goodItems.pages) {
        this.isLoading = true
        let res = await getHomeRecommend(this.url, {
          subType,
          pageSize,
          page
        })
        let items = tabItem.goodItems.items
        tabItem.goodItems = res.result.goodsItems[subType]
        tabItem.goodItems.items = [...items, ...tabItem.goodItems.items]
        this.isLoading = false
      }
    }
  }
}
</script>

<style lang="scss">
page {
  height: 100%;
  background-color: #f4f4f4;
}
.viewport {
  display: flex;
  flex-direction: column;
  height: 100%;
  padding: 180rpx 0 0;
  position: relative;
}
.cover {
  width: 750rpx;
  height: 225rpx;
  border-radius: 0 0 40rpx 40rpx;
  overflow: hidden;
  position: absolute;
  left: 0;
  top: 0;
}
.tabs {
  display: flex;
  justify-content: space-evenly;
  height: 100rpx;
  line-height: 90rpx;
  margin: 0 20rpx;
  font-size: 28rpx;
  border-radius: 10rpx;
  box-shadow: 0 4rpx 5rpx rgba(200, 200, 200, 0.3);
  color: #333;
  background-color: #fff;
  position: relative;
  z-index: 9;
  .text {
    margin: 0 20rpx;
    position: relative;
  }
  .active {
    &::after {
      content: '';
      width: 40rpx;
      height: 4rpx;
      transform: translate(-50%);
      background-color: #27ba9b;
      position: absolute;
      left: 50%;
      bottom: 24rpx;
    }
  }
}
.scroll-view {
  flex: 1;
  overflow: hidden;
}
.goods {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  padding: 0 20rpx 20rpx;
  .navigator {
    width: 345rpx;
    padding: 20rpx;
    margin-top: 20rpx;
    border-radius: 10rpx;
    background-color: #fff;
  }
  .thumb {
    width: 305rpx;
    height: 305rpx;
  }
  .name {
    height: 88rpx;
    font-size: 26rpx;
  }
  .price {
    line-height: 1;
    color: #cf4444;
    font-size: 30rpx;
  }
}
.goods .symbol,
.goods .decimal {
  font-size: 70%;
}
</style>
